Switch mechanism



June 23, 1965 D. J. ARM-:BERG ETAL 3,258,566

SWITCH MECHANI SM Filed Dec. 4. 1963 2 Sheets-Sheet l DON J. ARA/EBERGHAROLD E. W/-l/T/NG Y 5 MERLIN K TURNBULL June 28, 1966 D, J. ARNEBERGETAL. 3,258,566

SWITCH MECHANI SM United States Patent Office 3,258,566 Patented June28, 1966 3,258,566 SWITCH MECHANISM Don J. Arneberg and Harold E.Whiting, Milwaukee, and Merlin Y. Turnbull, Brookfield, Wis., assignorsto Square D Company, Park Ridge, Ill., a corporation of Michigan FiledDec. 4, 1963, Ser. No. 327,952 14 Claims. (Cl. 200-124) This inventionrelates to switch mechanisms and is more particularly concerned with aprotective switch which will respond to excess current in any one of aplurality of circuits.

It is an object of the present invention to provide a trip free thermaloverload switch mechanism which can be manually reset by a singleoperator, providing the current overload conditions in a plurality ofcircuits have -been corrected and wherein the switch mechanism includesa single actuator having integrally formed levers extending at differentangles from one another to provide the trip free and switching functionsfor the mechanisms.

Another object of the present invention is to provide a tripfreeoverload relay which has a housing deiining a cavity wherein the tripfree switch operating mechanism is enclosed and to provide the housingwith an external recess which is connected to the internal cavity by apassage in a wall of the housing and which is arranged to removablyposition a separately enclosed switch, preferably of the snap actingtype, which has a contact operator accessible to the passage foractuation by a lever of the operating mechanism disposed within thecavity.

An additional object of the present invention i-s to provide a trip freemelting alloy type overload relay unit with an arrangement forconverting the unit from a two to a three element unit.

A further object of the present invention is to provide a trip freemelting alloy type overload relay or protective switch whichincorporates a novel trip free plunger operated overload mechanism whichis arranged to be actuated in response to an overload condition in anyone of a plurality of circuits for actuating an operator of a separatelyenclosed switch which is externally accessible for removal andreplacement as a unit -and to provide the relay with an opening in aIbottom wall which will permit the relay to bereadily converted from atwo element to a three element melting alloy type overload relay.

Further objects and features of the invention will be readily apparentto those skilled in the art from the specication and appended drawingillustrating certain preferred embodiments in which:

FIG. 1 is a top plan view of the trip free overload relay incorporatingthe features of the present invention.

FIG. 2 is a side elevational View of the relay in FIG. 1.

FIG. 3 is a bottom plan view of the rel-ay in FIG. 1.

FIG. 4 is a view showing certain internal parts of the relay with a topsection of the housing for the relay removed.

FIG. 5 is a cross-sectional view taken along line 5-5 in FIG. 1.

FIG. 6 is a cross-sectional view generally taken along line 6-6 in FIG.l.

FIGS. 7, 8 and 9 are cross-sectional views taken along lines 7-7 in FIG.1, respectively showing the position of the relay parts in the trippedposition, when the operating plunger is initially and fully depressed,and when the parts are in the reset position.

FIG. 10 is a cross-sectional view taken along line 9-9 in FIG. 1 withthe parts of the relay in the tripped position as in FIG. 7.

FIGS. `11 and 12 are cross-sectional views taken along line 11-11 inFIG. 1 with the parts of the relay respectively in the position when theoperating plunger is initially and fully depressed as in FIG. 8 and inthe reset position as in FIG. 9.

FIG. 13 is a view partly in section showing in detail certain of thecomponents of the current responsive means as used in the relay in FIG.l.

In the drawings, and in FIG. 2 particularly, the protective switch ortrip free overload relay includes a housing 20 formed by a pair ofmating parts 21 and 22 which are preferably molded of a suitableinsulating material. The housing parts 21 and 22 when secured togetherare mounted on a base 23 and `are arranged to define an internal cavity24 which has a bottom wall 26, shown in FIGS. 7-12, a pair of spaced endwalls 28 and 30, shown in FIGS. l and 6, and a pair of spaced side walls32 and 34, shown in FIG. 5. As shown in FIG. 6, a pair of spacedpartitions 36 and 38 extending between the side walls 32 and 34 andparallel to the end walls 28 and 30 divide the cavity 24 into threeparallel compartments 40, 41 and 42. The end wall 28 and the adjacentside wall 32 of housing parts 21 and 22 are shaped to provide anexternal recess 44 as shown in FIGS. 2 and 5 in which a separatelyenclosed snap switch 46` is positioned. As shown in FIGS. 7-9, the sidewall 32 of the housing part 22 which forms `a portion of the recess 44is provided with a passage 48 which interconnects the recess 44 with thecompartment 40. As shown in FIG. 7, each of the partitions 36 and 38 isprovided with la slot 50 extending upwardly from the bottom wall 26providing a passage extending between the end walls 28 and 30 andtransversely to the compartments 40-42. The end walls 28 and 30 of thehousing part 22 are respectively provided with slots 51 and 52, as shownin FIGS. 4 and 6, which extend toward the lbottom wall 26 and arealigned with the slot-s 50 in the partitions 36 and 38. The slots S1 and52 are provided with closed ends to provide stops 53 and 54. The closedends are preferably provided by the bottom edge of the housing part 21when the housing parts 21 and 22 are assembled. Each of the compartments40-42 is respectively provided with shelves 40a, 41a and 42a extendinginwardly from the side walls 32 and 34. The shelves 40a, 41a and 42a arecoplanar with each other and are vertically spaced beneath the topsurfaces of the housing part 21 as shown in FIG. 2. Similarly, coplanarwith shelves 40a, 41a and 42a and extending inwardly from side wall 34are shelves 40b, 41b, and 4217 as shown in FIG. l. The shelves 40a, 40h,41a, 41h, 42a and 42b are each arranged to support metal conductors 55which are provided at one end with a threaded opening to receive a screw56 and on the other end are provided with a suitable means indicated bynumeral 57 for securing a current conducting member, not shown, totheconductors 55. The partitions 36 and 38 in housing part 21, as shown inFIGS. l() and ll, are provided with slots 58a and 60u which extenddownwardly toward the bottom wall 26 along an axis that is disposedparallel to the axis of slots 50. The housing part 22 is also providedwith slots 58h and 60]: which are located as in FIG. 4 to be verticallyaligned with slots with slots 58a and 60o. The slots 58a and 58b arearranged to guide one arm 116@ of a reset plunger 112 and the slots 60aand 60b are arranged to guide a second arm 116b of the reset plunger112.

Positioned in the respective compartments 40-42 are melting :alloy typecurrent responsive means 40e, 41C and 42e which, as shown in FIG. 1, aresecured to respective ones of the conductors by screws 56. Each currentresponsive means includes a solder type current responsive .unit whichhas a heater element connected in series With a circuit to be monitored.A typical example of 3 a current responsive unit is disclosed in the VanValkenburg Patent 1,752,514, issued April 1, 1930. When the currentflowing .through the monitored circuit and therefore the heating elementof the current responsive means exceeds a predetermined value, thesolder within the unit melts, permitting a ratchet wheel of the currentresponsive means is in a solid state and surrounds the shaft spectivecurrent responsive means are designated as 40d, 41d and 42d. Normallythe solder of the current responsive means is in a solid state andsurrounds the shaft whereon the ratchet wheel is fixed to hold theratchet wheels 40d-42d against rotation. When the current responsivemeans, e.g., current responsive means 41C, is subjected to abnormalcurrent flow, the ratchet wheel 41d is free to rotate. After theabnormal current flow ceases, the solder again solidies to maintain theratchet wheel 41d against rotation.

Movable within the cavity 24 in the passage defined by the slots 50 inthe partitions is a rod-like actuator 62 which is arranged to be guidedin a vertical path of movement by slots 51 and 52. The closed ends orstops 53 and 54 of the slots 51 and 52 limit the upward verticalmovement of the actuator 62. The actuator, which is preferably formed ofa molded insulating material, is rotatable in the slots 51 and 52 and asshown in FIG. 4, is formed to have a plurality of levers or projectionsintegrally formed thereon which are spaced along the longitudinal axisof the actuator 62. These levers include three spaced levers 62a, 62band 62C which extend in a common plane and which are spaced along thelongitudinal axis of the actuator 62 `to extend respectively intocompartments 40, 41 and 42. Preferably the levers 62d, 62b and 62C arelocated on the actuator to be proximate the left side of thecompartmen-ts 40-42 as shown in FIG. 6. The aforementioned plurality oflevers on actuator 62 also includes a single lever 62d locatedsubstantially at the longitudinal center of the actuator 62 and which iscoplanar with levers 62a, b and c and extends in a direction opposite tothe direction in which levers 62a, b and c extend, as shown in FIGS.10-l2. The plurality of levers on actuator 62 also includes a lever 62ewhich extends in a plane perpendicular to the plane of levers 62a, b, cand d and is located longitudinally on the actuator 62 to be inalignment with the passage 48 as shown in FIGS. 7-9. Finally theplurality of levers extending from actuator 62 includes a pair of levers62]c and 62g which are spaced along the longitudinal axis of actuator 62on opposite sides of lever 62d as in FIG. 4 and are ang-ularly orientedas shown in FIGS. 7-10, to extend in a common plane which is at an acuteangle -to the plane of levers 62a, b and c and at an obtuse angle fromthe plane passing throu-gh lever 62e and the axis of actuator 62.

y A suitable guide slot 64 in housing part 22, which is verticallyaligned with lever 62d as shown in FIG. 4, provides a guide for avertically movable element or slider 66 shown in FIGS. 10-12. The slider66 is urged into constant engagement with lever 62d by a biasing spring68 which has one end resting on the bottom surface 26 and its other endin engagement with a spring seat 66a on slider 66. The spring seat 66ais located, as shown in FIG. 12, ybetween a pair of spaced arms 66b and66C which -have their outer surfaces in sliding engagement with thewalls of slot 64 for guiding slider 66 in its vertical movement. Thearms 66b and 66C are interconnected by a central portion 66d which hasits upper surface shaped to provide a surface portion 66e which is inconstant engagement with lever 62d and a relieved portion 66]c whichprovides clearance between slider 66 and the actuator 62 when the partsof the device are in the position shown in FIG. 12. The slider 66 andspring 68 comprise a biasing means which constantly urges the actuator62 upwardly into engagement with stops 53 and 54 and as the slider 66 isarranged to engage the lever 62d at a point spaced from the longitudinalaxis of actuator 62, the actuator 62 is constantly urged in acounter-clockwise direction of rotation as shown in FIGS. 10-12.

In this connection it is to be noted that because lthe lever 62d islocated substantially in the longitudinal center of actuator 62, tiltingof the actuator 62 by the biasing means including slider 66 isminimized, and the actuator 62 engages both stops 53 and 54 with asubstantially equal pressure.

The housing part 22 is also provided with three guide slots 70a, 70b,and 70C which are respectively vertically aligned with levers 62a, b andc as shown in FIG. 4. Each of these slots 70a, b and c have a movableele-ment or slider therein designated as 72a, b and c. The sliders 72a,b an c which are respectively shown in FIGS. 8, 5 and l0, are constantlybiased upwardly by springs 74a, b and c. The springs 74d and c havetheir respective ends positioned by posts 76a and c extending upwardlyin slots 70a and 70C from the bottom wall 26. The spring 74b ispositioned by a removable member 78 which is positioned in an opening`80 in the bottom wall 26 at the base of slot 70b, as will behereinafter described.

Each of the sliders 72a, b and c positions a latching member 82a, b andc. As all of the sliders and latching members are identical, only theslider 72b and the latching `member 82b will be described, reference tobe had to FIGS. 4, 5 and 13.

As shown in FIG. 4, the slot 70b is provided with oppositely facinggrooves 70d adjacent the side wall 34. The slider 72b as shown in FIGS.5 and 13 has a vertical back portion 84 from which a pair of ribsextend. The ribs are received in grooves 70d for guiding the slidervertically. Extending horizontally from the back portion 84 is a ledge88 providing a surface that is engageable with lever 62a. Extendingoutwardly from the back portion 84 in the ledge 88 is an opening 90 anda pair of vertically extending ribs 92 which are disposed on oppositesides of the opening. Depending downwardly from the free ends of ledge`88 is a portion 94 which serves to further guide the slider .72b in theslot 70b. A pair of spaced walls 96 are formed to extend downwardly fromthe ledge 88 between the lback portion 84 and the guide portion 94. Thewalls 96 are each provided with a notch 98 located at the intersectionof Ithe guide portion 94 and the bottom surface of ledge 88 and have aportion removed as at 89 (FIG. 5) to provide a confinement for an end ofthe spring 74b. The latching member 82b is preferably formed from asingle metal part to have a base portion 100 and a latching portion 102.The base portion 100 and latching portion 102 are interconnected by acurved portion 104 which is arranged so the latching portion 102 isnon-perpendicular to and slightly inclined toward the base portion 100at an angle which, as shown in FIG. 13, is 7 degrees. Extendingoutwardly from the free end of the base portion 100 is a pair ofoppositely extending tongues 106 which are arranged to be received inthe notches 98 for pivotally positioning the latching member 82b andslider 72b when the base portion 100 is received between the spacedwalls 96 and the curved portion 104 extends through opening with thelatching portion 102 extending upwardly from the ledge 88. The baseportion may also be suitably embossed to 4provide a seat for the spring74a which normally urges the base portion into engagement with thebottom surface of the ledge 88 thereby causing the latching portion, tobe rotated clockwise to an inclined position as shown in the drawings.The latching portion 102 is provided with a pawl 108 which, when theslider is positioned as in FIG. 9, is arranged to engage the ratchetwheel 40d, and when the slider is in the posi-tion shown in FIG. 7, isarranged to be positioned above the ratchet wheel 40d. The latchingportion also includes a vertically extending reinforcing rib 110 whichhas its bottoni edge engageable with the upper surface of one of theribs 92 for limiting the counter clockwise rotation of the latchingportion 102 relative to the upper surface of the ledge 88.

The reset plunger 112, preferably formed of a molded insulatingmaterial, has a portion externally accessible of the housing 20 and apair of spaced arms 116a and 116b respectively movable in the slots 58aand 58b and 60a and 60b in the housing parts 21 and 22. The arms areinterconnected vby a bar 118 (FIG. 10) which is integrally for-med withthe arms 116a and b and located within the cavity 24. The bar 118 has adownwardly extending post 120 formed thereon at its mid portion whichpositions a spring 122 which has one end restin-g on bar 118 and itsother end resting on the bottom wall 26. An externally accessibleportion 119 on the plunger arms 116a and 116b preferably is formed of aseparate part of ymolded insulating material which is secured to theexternal ends of arms 116a and b to provide an arrangement where-by botharms 116e and b may be simultaneously moved by an external force againstthe force of spring 122.

Each of the arms 116a and 116b are identical and hence only arm 116awill be described, reference being had to FIG. 11. The arm 116a has aportion 124 extending perpendicular to bar 118 and aligned with lever62g. 'Ihe portion 124 is provided with an upper surface 126 whichengages an internal surface providing the ceiling for the cavity 24 tolimit the upward vertical movement of the arm 116a by spring 122. Theportion 124 also has a notch 128 formed by -a vertical side wall 130 anda horizontal ceiling 132 vertically spaced below surface 126.

The vertical side wall 130 is engaged by a vertical portion 134 on theend of lever 62g and the ceiling 132 is arranged to engage a flat endportion 136 on the end of lever 62g which is disposed perpendicular tothe vertical portion 134. The vertical movement of lthe arm 116e in adownward direction is limited by the bar 118 as it engages a portion ofthe housing part 22.

The separately enclosed snap switch 46 which is most clearly shown inFIGS. 2, 5 vand 7-9, is provided with an external housing which isshaped to be received in the external recess 44. The housing is mountedon a base 140 which has a pair of spaced ears 142 arranged to bereceived in a pair of spaced notches in the base 23 which also supportsthe housing 22. The base 140 has a bent portion having an opening whichreceives a bolt 146, shown in FIG. 2, which is threaded into an openingin base 23 for securing the base 140 to base 23. The opening in base 140is located so the bolt 146 is accessible from the side 32 of the housing20. As shown in FIG. 7, the snap switch 46 has an actuator 148 extendingexternal to its housing in a position to be partly received in passage48 when the snap switch is installed in recess 44. The actuator 148 isarranged to Imove an overcenter snap acting member 150 which has amovable contact 152 on a free end. The movable contact 152 is arrangedto engage either of two st-ationary contacts 154 or 156 and to 4movetherebetween with a snap action. The movable contact is electricallyconnected with a wire connecting terminal 158. Similarly, t-hestationary contacts 154 and 156 are electrically connected to terminals160 and 162, as shown in FIG. 2.

When the overload relay is assembled, the spring 68 and slider 66 arepositioned in slot 64. The springs 74a and c and the sliders 72a and c,including the associated latching members 82a and c, are similarlypositioned in the guide slots 70a and 70C and the plunger return spring122 is positioned on the bottom wall 26. The actuator 62 is thenpositioned on the housing part 22 with its respective ends in slots 51and 56 and its levers 62a, c and d in engagement with sliders 72a, 72cand 66. The upper housing part 21 which `includes the assembled plunger112 is then positioned on the lower housing part 22 which in turn ispositioned on the base 23. The assembly of the foregoing parts iscompleted when a pair of screws 166 as shown in FIG. 6, which passthrough mounting bosses 168 on the upper housing part 21 and throughopenings 171 in recesses 172 in the lower housing part as shown in FIG.4, are engaged in threaded openings in the base 23. The assembly is thencompleted when the current responsive means 40e and 42C are secured toconductors 55 so the latching members 82 are lin engagement with theratchet wheels 40d and 42d and the snap` switch 46 is installed inrecess 44 as when screw 146 is threaded in base 23.

The overload relay 20 when thus assembled will be capable of respondingto an excess current condition in only two circuits as the partsproviding the overcurrent protection which are intended to be includedin the center compartment 41 have been purposely omitted. While theparts ,which would provide overcurrent protection in the centercompartment 41 could have been included during the assembly of the relay20, in many circuits overcurrent protection in two circuits is inaccordance with conventional practices thus the relay 20 will notinclude an excess of costly components. However, the device can bereadily converted from a device which will respond to overcurrentconditions in two circuits to a device which will respond to overcurrentconditions in three circuits with little difculty, as follows.

As previously described, and as shown in FIGS. 3 and 5, the slot 70b isexposed through an opening 80 in the bottom wall 26 and an opening 170in the base 23, both of which are rectangular in shape with the opening170 having a slightly greater width Ithan opening 80. Insertable throughthe openings and 170 is the member 78 which has a cylindrical portion176 sized to be received in a counterbored portion of the slot 7Gb. Theportion 176 of member 78 which is received in slot 70b is tubular toprovide a confinement and spring seat for one end of the spring 74b. Themember 78 is provided with a locking and seating portion 178 locatedbetween the portion 176 and a portion 18) extending below the lockingportion 178 which, as shown in FIG. 3, at its exposed end has a suitableslot 182 to receive a tool, such as a screw driver, for rotating .themember 78. The locking portion 178 is generally rectangular in shapehaving a width greater than the portion of the opening 7011 surroundingthe counterbore and less than the opening 170. The portion 178 includesoppositely extending locking and camming portions 184 and 185 havingends 186 and 187 which are provided with a curved surface having aradius centered at the center of the cylindrical outer surface of member78. Extending inwardly from ends 186 and 187 are oppositely facingnotches 188 and 189 which extend from the ends 186 and 187 to theexternal cylindrical surface of member 78.

The notches 188 and 189 thus divide each of the portions 184 and 185, asshown in FIGS. 3 and 13, into two parts with t-he parts of the portion184 designated as 190 and 191 and the parts yof portions 185 designatedas 192 and 193. The parts 190 and 192 are located at diametricallyopposite corners of the locking portion 178 and are -substantiallyrectangular in cross section with the surfaces facing portion 180 in aplane normal to the axis of member 78. The parts 191 and 193 which aredisposed at the remaining diametrically opposite corners of the lockingportions are formed as inclined resilient lugs with a parallelogramcross-section having end surfaces parallel to the axis of member 78 andside surfaces inclined to the axis of member '78. The intersection ofthe end surface adjacent the notch 189 and the side surface facingportion 180 is coplanar with the surface of parts 191 and 193 facingportion 180.

As shown in FIG. 3, the base 23 is provided with a pair of raisedpimple-like bosses 194 adjacent the l-onger sides of opening 170. Thebosses 194 are located on the centerline of the -opening 178 which isperpendicular to the longer sides of the rectangular opening and arespaced adjacent the longer sidesito be received inthe notches 188 and189when the'member 7S is inserted through openings and rotated onequarter turn to the position indicated by broken lines in FIG. 3.

When the -relay is converted to a device whichwill respond toovercurrent conditions in three circuits, the slider 72b includinglatching member 82b`, is inserted through opening 170 and opening S0into slot 7017. The spring 74b is then positioned in the tubular portionof the upwardly extendingcylindr'ical portion 176 of the removablemember 78 with one end of the spring 74b seatedon the base of thetubular portion. The assembled spring 74b and removable member 73 isthen inserted through opening 170 and opening 80 so that the cylindricalportion 176 is received in the counterbored portion of slot70b and thefree end of the springis seated upon k ing the rotation of the member78fthe inclined lugs 191 and 193, which are both inclined and exible,pass over the bosses 194 sothat the bosses 194 arereceived in notches188y and 189 to maintain the member 78 against rotation, as when thespring 7419 urges the member 78:

into tight engagement with the base 23. The current responsive'element41C is then positioned in compartment 41 with Ithe ratchet wheel 41d inengagement with the latching portion 102y of the latching member 82b.The current responsive means 41C is secured in position in compartment41 when the screws 56 are applied to secure the current responsive means41C to the metal conductors 55. The foregoing will complete theconversion of the relay to a device which will respond to currentconditions in three individual circuits.

In View of `the foregoing description, the operation of the overloadrelay is as follows, reference being had to FIGS. 7-12, wherein FIGS. 7and 10 illustrate the parts of the device when the device is in thetripped position, FIGS. 8 and ll illustrate the parts after the devicehas been tripped and the reset plunger 112 is fully depressed toposition the parts of the device in the reset position and FIGS. 9 and12 illustrate the positi-on of the parts of the device in the resetposition after the plunger has been released.

As was previously set forth, each of the current responsive means whichare positioned in the compartments 40, 41 and 42`includes an element40C, 41e and 42C which is connected in a circuit to be protected andincludes a heater element which in response to an excess current ilow inthe circuit causes the alloy within the element to become iluid so oneof the ratchet wheels 40d, 41d and 42d may rotate. The currentresponsive means in each of the compartments, 40, 41 and 42, alsoincludes a latching member 82a, g2b and 82C respectively carried bysliders 72a, 72b, and 72C which are biased by springs 74a, 74b and 74e.As the operation of each of the current responsive means is identical,although each is independently operable, the operation of the currentresponsive means 40C in compartment 4@ will be described, as shown inFIGS. 7-9. When parts lof the overload relay are in the trippedposition, as in FIG. 7, the pawl 108 is disengaged from and positionedabove the ratchet wheel 40d by the slider 72a which is moved upwardly bythe spring 74a to position the actuator 62 against the stops 53 and 54in slots 51 and 52, Also when the overload relay 20 is in the trippedposition, as shown in FIG. l0, the slider 66 is moved upwardly by spring68 to urge the actuator 62 into engagement with stops 53 and 54. Each ofthe springs 74a, 7411 and 74C are selected to exert greater force on thesliders 72a, 72b and 72C than is exerted by spring 63 on slider 66. Thuswhen any of the sliders 72a, b or c is in the position shown in FIG. 7,the actuator 62 will be rotated in a clockwise direction to a trippedposition wherein the surface. 134 of levers 62f and 62g engagesthesurfaces 130 on the portions 124 of t-he reset plunger 112. When theactuator is in the tripped position, the lever 62e is disengaged fromthe actuator 48 and the movable contact 152, of the snap switch 46engages the stationary contact 156 which may be connected in an'alarmcircuit, not shown, to indicate the relay is in a tripped condition.

When the plunger 112 is depressed from the tripped position, as in FIG.7, toward the position shown in FIG. 8, the actuator will not rotatefrom the position shown in FIG. 7. This is accomplished as theceilings132 of notches 12S-on the arms 116a and 116b engage the flat endsurfaces 136 on levers 62f and g and cause the actuator 62 to movedownwardly Without rotating in slots 51 and 52 to the position shown inFIG. 8 wherein the pawl 108 is beneath the ratchet wheel 40d. Theactuator 62 Vis constantly urged upwardly by the biasing means whichincludes the sliders which react against levers 62a, b, c and d, so thefrictional engagement is maintained between the ceilings 132 and flatend surfaces 136. Thus as long asthe downwarddepressive force ismaintained on the plunger 112 to both move and maintain the parts of thedevice in the position shown in FIG. 8, the actuator 62 will bemaintained in the position shown in FIG. 8.

When the depressing force on the plunger 112 is removed, the spring 122causes the plunger 112 to move upwardly in the guide slots 58a and b and60a and` b, from the position shown -in FIG. 8 to the position shown inFIG. 9. The upward movement of the plunger permits the actuator `62 andthe sliders 72a, b and c to move upwardly to a position wherein thepawls 108 on the respective latch members move into engagement with theratchet wheels 40d, 41d and 42d. If any of the ratchet wheels are freeto rotate the actuator 62 will be maintained in the position shown inFIG. `8 and will move to the tripped position shown in FIG. 7 becausethe bias provided by :any of the springs 74a, b or c exceeds the biasprovided by the spring 68.' If all of the ratchet wheels 40d, 41d and42d are nonrotatable, the respective pawls 16S will engage the ratchetwheels and thereby prevent further upward movement of the sliders 72a, band c. The sliders will be then maintained in the retracted positionshown in FIG. 9. The slider 66 which is biased upwardly by spring 68through lever 62d will cause the actuator 62 to move into engagementwith stops 53 and 54 and rotate counterclockwise to the position shownin FIG. 9 wherein the levers 62j and g are out of the path of verticalmovement of the notches 128 on the arms 116a and b of the reset plungerand the lever l62e is moved counterclockwise into engagement with theactuator 48. The counter-clockwise motion of the lever 62e will causethe actuator 48 to move the snap acting spring 150 of t-he snap switch46 so that the movable contact 152 engages the stationary contact 154.The stationary Contact may be connected in a suitable circuit, notshown, such as an actuating coil, of a device which is to be controlledby the cyrload relay according to the present invention. As previouslystated, when the actuator is in the reset position shown in FIG. 9, thelevers 62f and g are rotated so as to be out of the path of verticalmovement of the notches 128 on the reset plunger. Thus when the deviceis in the reset position, depression of the plunger to the resetposition will be without effect, so as to provide the device with a tripfree operation.

When the parts of the relay are in the reset position as shown in FIG.9, and an excess current condition occurs in yany of the currentresponsive devices in compartments 4G, 41 and 42, the ratchet. wheelassociated with the current responsive means 46c, 41o or 42C is free torotate. The slider which is operatively connected to the releasedratchet wheel is now free to move upwardly in its slot from the positionshown in FIG. 9 to the position in FIG. 7, wherein the slider engagesthe lever of the actuator 62 and causes the actuator to rotate andposition the parts as in FIG. 7, which has been previously described.

While certain preferred embodiments of the invention have beenspecifically disclosed, it is understood that the invention is notlimited thereto, as many variations will be readily apparent to thoseskilled in the art and the invention is to be given its broadestpossible interpretation within the terms of the following claims.

What is claimed is:

1. In a relay the combination comprising; an actuator bodily movable in:a vertical path and rotatable about a horizontal axis between a trippedposition and a reset position, stop means for limiting vertical movementof the actuator in one direction, a first and a second biasing meanseach arranged for moving the actuator in said one direction intoengagement with the stop means and each arranged for simultaneouslyurging the actuator in opposite directions of rotation, said firstbiasing means being arranged to urge the Iactuator toward the resetposition and including at least one vertically movable element having aconstant engagement with a portion of the actuator, said second biasingmeans including a plurality of vertically movable biasing elements eachengaging a different portion of the actuator at spaced intervals alongthe horizontal axis of the actuator, each of the elements of the secondbiasing means being movable from a reset position to a tripped positionwherein the element is elective to rotate the actuator to the trippedposition while the actuator is in engagement with the stop means and isbiased toward the reset position by the first biasing means, areleasable latch means for each of the elements of the second biasingmeans, each of said latch means being arranged when latched formaintaining the element associated therewith in the reset position andout of engagement with the actuator when the actuator is in engagementwith the stop means whereby said actuator is rotated to the resetposition by the first biasing means, each of said latch means also beingineffective when released to prevent movement of the element associatedtherewith toward the tripped position whereby the actuator is rotated tothe tripped position by said element, and a plunger vertically movablefrom an at rest position having a portion engageable with a portion ofthe actuator only when the actuator is in the tripped position, saidplunger having a biasing means for constantly urging the plunger towardthe at rest position, said engageable portions of the actuator and theplunger being arranged so the actuator is constantly maintained in thetripped position and in engagement with the plunger when the actuator ismoved by the plunger along its vertical path of movement out ofengagement wit-h the stop means to a position wherein any previouslytripped element of the second biasing means is moved from the trippedposition to the reset position, said engageable portions on the actuatorand plunger also being arranged so the actuator is moved to the resetposition by said first biasing means when all of the elements of thesecond biasing means are maintained in the reset position by thelatching means and the force on the plunger is released.

2. In a -relay the combination comprising; a rod-like actuator bodilymovable in a `vertical path and rotatable about a horizontal axisbetween a tripped position and a reset position, a plurality oflever-like portions extending from said actuator, stop means forlimiting vertical movement of the actuator in one direction, a lfirstand a second biasing means each arranged for engaging different leverportions of the actuator for Amoving the actuator in said one directioninto engagement with the stop means and each arranged for:simultaneously urging the actuator in opposite directions of rotationwhen the actuator is in engagement with the stop means, said firstbiasing means being arranged to urge the actuator toward the resetposition and including at least one vertically movable element having aconstant engagement with a lever portion of the actuator, said lsecondbiasing means including a plurality of vertically 4movable biasingelements each engaging a different lever porti-on of the actuator atspaced intervals along the horizontal axis `of the actuator, each of theelements of said second biasing mean-s being movable from a resetposition to a tripped position wherein the element enga-ges a leverportion and is effective to rotate the actuator to the tripped positionwhile the actuator is in engagement with the stop means and is biasedtoward the reset position by the first biasing means, a releasable latchfor each of the elements of the second biasing means, each of said latchmeans being arranged when latched Afor maintaining t-he elementassociated therewith in the reset position and out of engagement withthe lever portion of the actuator when the actuator is in engagementwith the stop means whereby said actuator is rotated to the resetposition 'by the first biasing means, each of said latch means alsobeing ineffective when released to prevent movement of the elementassociated therewith toward the tripped position whereby the actuator isrotated to the tripped position by said element, and a plungervertically movable from an at rest .position along an axis parallel tothe vertical path of movement of the actuator and having a portionengageable with another lever portion of the actuator only when theactuator is in the tripped position, said plunger having a biasing meansfor constantly urging the plunger in said one direction, said engageableportions of the actuator and the lever portion of the plunger beingarranged so the actuator is constantly maintained in the trippedposition and in engagement with the lever portions of the plunger whenthe actuator is moved by the plunger along its vertical path of movementout of engagement with t-he st-op means when the plunger is depressed bya force which is maintained against the biasing means of the plunger formoving the plunger from the at rest position to a position wherein anypreviously tripped element of t-he second biasing means is moved fromthe tripped position to the reset position, said engageable portions onthe actuator and the lever portions on the plunger also being arrangedso the actuator is moved to the reset position by said first biasingmeans when all of the elements of the second biasing means aremaintained in the reset .position by the latching means and the force onthe plunger is released and its biasing means `moves the plunger towardthe at rest position.

3. In a trip free overload relay, the combination comprising; a housingproviding an internal cavity, an actuator guided -for vertical movementin the cavity, stop means for limiting said movement of the actuator inone direction, said actuator being rotatable in the cavity and having a.plurality of spaced levers extending in a common direction and at leastone lever extending in a direction opposite said common direction, afirst biasing means engageable with said oppositely extending lever forurging the actuator in one direction of rotation and in a verticaldirection into engagement with t-he stop means, a plurality of currentresponsive second biasing means each having; a spring biased portionwithin the cavity engageable with one of the plurality of levers of theactuator and movable between a tripped and reset position and biased formoving the actuator into engagement with the stop means and for rotatingthe actuator in opposition to said first biasing means in a directionopposite to said one direction of rotation, a releasable latch means formaintaining said spring biased portion in a resetposition, a verticallymovable spring biased reset plunger, cooperating portions on the resetplunger and actuator arranged for mutual engagement and for limitingrotational move-ment of the actuator to one rotational position 'by thesecond biasing means, said cooperating -portions of the actuator and theplunger -being arranged so the actuator is constantly maintained in thersaid one rotational position and in engagement with the plunger whenthe plunger is depressed for vertically moving the plunger and theactuator out of engagement with the stop means and for moving the springbiased .portions of the current responsive second biasing means to thereset position, said cooperating portions on the plunger and actuatoralso being arranged so the actuator is moved against the stop means bysaid first biasing means when all of the spring biased portion means arein the reset position and the force on the plunger is released.

4. The combination as recited in claim 3 wherein the cavity is providedwith an opening in a bottornwall through which only one of the -springbiased portions may be inserted and wherein t-he housing is providedwith a top surface having means thereon for securing the cur- -rentresponsive releasable latch means.

5. The combination as recited in claim 3 wherein a separately enclosedsnap switch is received in an externally accessible recess in thehousing and wherein the switch has an actuator in engagement with alever on the actuator.

y6. In a current responsive means for an overload relay, the combinationcomprising: a fusible alloy type current responsive element having anormally fixed ratchet wheel which is rotatable when an excess currentpasses through the element, a slider having a iirst portion guided frommovement between two positions in the housing by a slot formed in aportion of a housing for the relay and` a second portion providing anupper surface facing the ratchet wheel and a lower surface facing awayfrom the ratchet wheel, an L-shaped latching member having a baseportion juxtaposed to the lower surface and having a first end pivotedon a portion of the lower surface, said latching member also having alatching portion extending upwardly from a second end of they baseportion which is disposed remote `from the iirst end at an angleinclined to the uppersurface when the base portion is in engagement withthe lower surface, and a pawl on said latching portion arrangedto-engage the ratchet wheel when the slider is in one of its twopositions, and a spring having one end in engagement with a portion ofthe base portion disposed-between the rst'and second ends and arrangedto constantly urge the base portion on its pivot into engagement withthe lower surface and bias the slider to a second of its two positions.

7. The combination as recited in claim 6 wherein the lbase portion andthe latching portion of the latching member are interconnected by acurved portion which extends through an opening between the first andsecond portions of the slider.

8. In a relay the combination comprising: a housing having; an internalcavity and an external recess with a passage extending between thecavity and recess, a sepiarately enclosed snap switch removably securedWithin the recess, said switch having an outer wall forming acontinuation of an outer wall of the housing-and a contact actuatorexposed to the passage when the switch is positioned in the recess, aplurality of current responsive means each including a movable elementpositioned wi-thin the cavity and an actuator movable within the cavity,said actuator having individual portions engaged bythe respectiveelements of each of the current respons-ive means and having anadditional portion disposed to move into engagement and actuate thecontact actuator of the switch in response to the operationl of any oneof the elements of the current responsive means.

9. The combination as reci-ted in claim 8 whereinthe housing has anopening in its bottom wall for passing the movable element of only oneof the current responsive means into position in the cavity.

it). lIn a relay the combination comprising: a housing having aninternal cavity with at least two partitions extending perpendicular toa bottom and top wall of the housing thereby dividing the cavity intothree spaced compartments, a current responsive means in each of thecompartments, each of said current responsive means including a currentresponsive element mounted on the top wall and a spring biased latchmeans having a portion linearly movable between the top and the bottomwalls and a portion engageable with the current responsive element,

i2 a passage inthe bottom Wall extending from the exterior ofthe-housing into one of said compartments for passing one of the latchmeans through said passage into the said one compartment and a coverclosing said passage when thesaidone latch means is positioned in thesaid one compartment.

'1-1. In alrelay the combination comprising, a housing having aninternal cavity with a bottom wall and partitions dividing the cavityinto a plurality of compartments, a unitary actuator vertically movablein the housing and extending transversely across all of thecompartments, a4 plurality o-f'levers integrally formed and spaced onthe actuator each aligned-for movementin one of the cornpartments,acurrent responsive current means individual to each of thecompartments, each of said current responsive means including a memberhaving a portion engageable with one of the levers to movesaidvact-uator to a tripped position and a portion having a latchingsurface. thereon, and a current responsive element having a releasableportion engage-able by the latching surface ofk said member formaintaining the member in a reset position during normal conditions ofcurrent flow and for releasing said latching surface during abnormalconditions of current flow.

12. In a trip free overload relay, the combination` comprising: ahousing having an internal cavity defined bya bottom wall, a pair` ofparallel end walls, a pair of parallel side walls, anda pair ofspaced.`partitions extending between the side walls and parallelA to the endwalls dividing the cavity into three parallel compartments, a rotatablerod-like actuator extending between the end walls and transversely tothe compartments, a pair of slots in the end walls for guiding theactuator along a path of movement perpendicular to. the bottom wall andarranged to providestops for limiting the movement of the actuator in adirection away from the bottom wall, a plurality of levers integrallyformed on the rodlike actuatonsaid levers comprising; three spacedlevers extendingin a` common plane and each arranged to, ex-` tend intoone of the compartments, a. rst single leverv centrally located on theactuator and extending in a direction opposite to the three levers, asecond single lever extending perpendicular to the plane of said threelevers and located `on the actuator to be in4 alignment with the passageand a pair of ,levers spaced on opposite sides of the first singlelever. and extending in a plane disposed at an acute angle from the.plane. of the.

three levers and at an angle obtuse from the. second single lever, valirst and a second biasing means each arranged for moving the actuatorinthe slots into engagement with the stops and each arranged forsimultaneously. urging the actuator in opposite directions` ofrotation,A

said first biasing means including a spring biased vertically movableelement in constant engagement with the first lever and arranged forrotating the actuator to a reset position, said second biasing meansincluding a current responsive means in each lcompartment with each ofthe current responsive means including a ratchet wheel fusible alloytype -current responsive element and a spring biased latch means havinga first portion engageable with and arranged to be releasably held vbythe ratchet wheel and a second portion engageable with one of the leversof-the set of levers, each of said current responsive means beingarranged to be held. in the reset position when the rst portion is heldby the ratchet wheel andto move the actuator into engagement with thestops and rotate the actuator in opposition to the rst biasing means toa tripped position when the first portion is released from the ratchetwheel in response to an excess current flow through the currentresponsive element, a spring biased plunger externally accessible of thehousing having a pair of spaced arms movable in a plane perpendicular tothe bottom wall and parallel to the path of movement of the actuator,said arms being spaced to engage the levers of said pair` of levers ofthe actuator only When the actuator is in the tripped position andhaving a notched portion arranged to engage a at end portion on an endof each of the levers for limiting rotational movement of the actuatorto the tripped position, said notched and at end portions being arrangedso the actuator is constantly maintained in the tripped position whenthe plunger is depressed against the bias of said first and second biasmeans for vertically moving the plunger and the actuator out ofengagement with the stops and for moving the second bias means to thereset position, said notched and flat end portions also being arrangedso the actuator is rotated and moved by said rst bias means intoengagement with the stops and rotated to the reset position when all ofthe current responsive means are held in the reset position and thedepressing force on the plunger is released.

13. The combination as recited in claim 12 which includes a cover whichcloses an opening in the bottom wall of the housing which extends intothe internal cavity and exposes the central compartment of the threeparallel compartments to the exterior of the bottom Wall when the coveris detached from said opening, said opening being sized and located topermit insertion of the latch means of the current responsive means intoposition in said central compartment and a portion on the coverReferences Cited by the Examiner UNITED STATES PATENTS 1,729,880 10/1929Krantz et al. 200--133 X 1,752,514 4/1930 Van Valkenburg 200-1241,755,231 4/1930 Van Valkenburg 200-124 1,886,608 11/1932 Van Valkenburg200-124 2,971,072 2/ 1961 Willcox et al. 20G-124 3,147,351 9/1964Brandenburg 200-124 3,179,757 4/ 1965 Brandenburg 200--124 BERNARD A.GILHEANY, Primary Examiner. H. B. GILSON, Assistant Examiner.

6. IN A CURRENT RESPONSIVE MEANS FOR AN OVERLOAD RELAY, THE COMBINATIONCOMPRISING: A FUSIBLE ALLOY TYPE CURRENT RESPONSIVE ELEMENT HAVING ANORMALLY FIXED RATCHET WHEEL WHICH IS ROTATABLE WHEN AN EXCESS CURRENTPASSES THROUGH THE ELEMENT, A SLIDER HAVING A FIRST PORTION GUIDED FROMMOVEMENT BETWEEN TWO POSITIONS IN THE HOUSING BY A SLOT FORMED IN APORTION OF A HOUSING FOR THE RELAY AND A SECOND PORTION PROVIDING ANUPPER SURFACE FACING THE RATCHET WHEEL AND A LOWER SURFACE FACING AWAYFROM THE RATCH WHEEL, AN L-SHAPED LATCHING MEMBER HAVING A BASE PORTIONJUXTAPOSED TO THE LOWER SURFACE AND HAVING A FIRST END PIVOTED ON APORTION OF THE LOWER SURFACE, SAID LATCHING MEMBER ALSO HAVING ALATCHING PORTION EXTEND-